1. Field of the Invention
This invention pertains generally to games using tangible projectiles, and more particularly to an arrow broadhead structure used in archery.
2. Description of the Related Art
Throughout the ages, and even before recorded history, man has devised bows and arrows from readily available materials. Early arrows were likely simple wooden “sticks” or dowels that were sharpened to a point on one end, resembling a small spear. This geometry offers a well-streamlined outline, meaning that there is relatively little air drag. With this geometry, the arrow can travel a relatively greater distance. Unfortunately, the significant distance advantage is offset by a relatively small puncture in the target. Unless struck directly in a vital organ in a way sufficient to cause essentially immediate death, animals such as deer may simply run through a wooded or overgrown area and brush the arrow against the surrounding plants, creating sufficient drag to pull the arrow out. Even if the puncture ultimately proves fatal, the animal may travel a great distance before succumbing. Owing to the small hole and little external blood loss therefrom, the animal may also be difficult or impossible to track. This inability to quickly stop many animals renders these sharpened dowels relatively ineffective, while causing unnecessary suffering and loss.
Later arrows were tipped with sharpened or “chiseled” rock. These stone arrow heads offered a larger, sharper and harder arrow head. Unfortunately, the larger arrow head is also associated with a substantially higher coefficient of drag through the air, meaning the arrow will slow down much more than a sharpened dowel. In addition, the larger and heavier arrow head will also tend to divert he air in flight undesirably. The added drag and the flight diversion both separately and independently reduce the distance from a target for an archer to get a successful shot.
Mankind progressed from the stone age into the bronze age, enabling the production of much thinner and less massive arrow heads. These arrow heads had reduced coefficients of drag when compared to stone, while not sacrificing the size and associated effectiveness of the arrow head. Nevertheless, and still perpetuated today, there are several types of arrow heads in common use.
One type of arrowhead in common use today is the field tip, which has a geometry similar to that of the early sharpened dowel. The tip will typically be an elongate point, generally with an initial taper and a longer body designed to slip over and circumscribe a cylindrical arrow shaft. This tip will typically be metal, ands will ordinarily endure repeated strikes into lesser materials such as straw targets and, in the event of a misfire, dirt and sand. As already noted herein above, the field tip has little utility in the hunting of larger game, but can be useful for smaller animals such as rabbits.
Another common type of arrowhead in common use is the broadhead. This arrow head may have one or more blades that extend radially out from the arrow shaft, meaning that the size of the cut or puncture is greater than would be produced by a sharpened shaft or field tip. This arrowhead is most similar to the stone and bronze arrowheads, but with modern materials is much thinner, meaning less drag during flight, and also much sharper. This combination helps to improve the effectiveness of the arrow, both in effectiveness at quickly stopping the animal and also in improved tracking, since there is a greater likelihood of a blood trail that can be tracked.
Some broadheads have blades that are sharpened in both directions parallel to the longitudinal axis of the arrow shaft, meaning the arrowhead cuts into the target, and also has a cutting surface when being removed therefrom. This bidirectional blade improves the ease of removing the arrowhead from the target, but also means the arrow may be more readily shed by the animal moving through brush and trees.
An additional feature of some modern broadheads is a deployable cutting blade that in flight is aerodynamically configured, most closely resembling the aerodynamic field tip, but which through the force of impact deploys blades that extend radially, gaining the efficacy of a broadhead. As with the fixed broadheads, the cutting blade(s) may be unidirectionally or bidirectionally sharpened, depending upon the archer's preferences. Patents that are exemplary of deployable broadheads, where the arms are moved directly as a result of impact with a target, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 3,036,395 by Nelson, entitled “Releasing fish point”; U.S. Pat. No. 5,078,407 by Carlston et al, entitled “Expandable blade, composite plastic, broadhead hunting arrow tip”; U.S. Pat. No. 5,178,398 by Eddy, entitled “Hunting broadhead for arrows”; U.S. Pat. No. 5,286,035 by Ward, entitled “Archery hunting arrowhead”; U.S. Pat. No. 5,820,498 by Maleski, entitled “Broadhead for an arrow having expanding cutting blades and method of assembling same”; U.S. Pat. No. 5,879,252 by Johnson, entitled “Arrowhead”; U.S. Pat. No. 6,165,086 by Liechty, entitled “Arrowhead with a pivotal blade selectively positionable in a plurality of different cutting diameters”; 6,200,237 by Barrie, entitled “Sliding body expanding broadhead”; U.S. Pat. No. 6,322,464 by Sestak, entitled “Hunting arrowhead with broadhead and extendable blades”; U.S. Pat. No. 6,517,454 by Barrie et al, entitled “Broadhead with sliding, expanding blades”; U.S. Pat. No. 6,626,776 by Barrie et al, entitled “Expandable broadhead with multiple sliding blades”; U.S. Pat. No. 6,669,586 by Barrie et al, entitled “Expanding broadhead”; U.S. Pat. No. 6,830,523 by Kuhn, entitled “Mechanical broadhead arrowhead”; U.S. Pat. No. 6,910,979 by Barrie et al, entitled “Expandable broadhead”; U.S. Pat. No. 6,935,976 by Grace et al, entitled “Mechanical broadhead with sliding blades”; and U.S. Pat. No. 8,128,521 by Ulmer, entitled “Mechanical broadhead with pivoting, interlocking blades”.
While somewhat less relevant to the present invention, other artisans have added other apparatus such as masses and gears. Many of the following exemplary patents and published application incorporate such apparatus, and the contents and teachings of each are incorporated herein by reference: U.S. Pat. No. 3,138,383 by McKinzie, entitled “Dual purpose arrow head”; U.S. Pat. No. 4,973,060 by Herzing, entitled “Arrowhead with expandable blades”; U.S. Pat. No. 4,998,738 by Puckett, entitled “Broadhead hunting arrow”; U.S. Pat. No. 5,082,292 by Puckett et al, entitled “Broadhead with deployable cutting blades”; U.S. Pat. No. 5,083,798 by Massey, entitled “Expandable broadhead for an arrow”; U.S. Pat. No. 5,100,143 by Puckett, entitled “Broadhead hunting arrow”; U.S. Pat. No. 5,112,063 by Puckett, entitled “Tubular restraint for broadhead with deployable cutting blades”; U.S. Pat. No. 5,941,784 by Mizek, entitled “Arrowhead with interchangeable blades”; U.S. Pat. No. 6,270,435 by Sodaro, entitled “Arrowhead”; U.S. Pat. No. 6,595,881 by Grace et al, entitled “Expanding-blade archery broadhead”; U.S. Pat. No. 7,226,375 by Sanford, entitled “Expandable arrow broadhead for attachment to one end of an arrow shaft”; U.S. Pat. No. 7,713,151 by Fulton, entitled “Mechanical broadhead with expandable blades”; U.S. Pat. No. 7,713,152 by Tentler et al, entitled “Arrowhead with unfolding blades”; U.S. Pat. No. 8,118,694 by Oliveira, entitled “Arrow tip with driven deployable retractable blade members”; and US published application 2010/0173734 by Robbins, entitled “Concealed broad head arrow tip and associated methods”.
As may be appreciated from the aforementioned patents, many forms of blade retention for deployable broadheads have been used. These typically require the use of additional components such as rubber bands, clips, gears, and other mechanisms and apparatus. These additional components in some cases require the use of consumable materials, such as in the case of rubber bands and the like, and require undesirable extra time to prepare the arrow before and subsequent to flight. Apparatus such as gears and other mechanical mechanisms add undesirable weight and expense. Both consumables and apparatus have a separate chance of failure, meaning a greater likelihood that the arrow will not perform as intended or desired. The extra materials also undesirably increase the cost of using the arrows as well.
The Mizek patent incorporated by reference herein above overcomes many of the deficiencies of the prior art by providing a foil or plate metal member having a pair of raised portions that engage with corresponding recesses within the blades. This combination of raised portions in the foil and recesses in the blades provides a low-force engagement there between, permitting the blades to be retained during flight and deployed with blade-to-target impact. This construction is relatively simpler and more reliable than the prior art consumables and gears and other drive mechanisms. Nevertheless, the formed foil adds significant expense. In addition, the separate formed foils used for each blade can easily become unequal or unbalanced, meaning that the blades do not deploy equally. While this is in most instances inconsequential, if one blade deploys during flight the arrow will be drastically pulled off target. Further, the foil may relatively easily be damaged or deformed during use, again altering the characteristics between the two deployed blades.
In addition to the aforementioned patents, Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein.